The MOS gate length is continuously downscaling because of the need of higher performance and cost-effectiveness. In addition to the fabrication process, the device architecture is being more and more complex and parameters extraction need to be adapted.

First in this thesis, the effects of high pressure final anneal with hydrogen (HPH2) or deuterium (HPD2) on MOSFET properties is investigated. The transport performances and reliability degradation comparison allow to consider HPD2 as a good compromise. The effect of a silicon-germanium (SiGe) channel is also studied. It is demonstrated that SiGe channel decreases defects located in the high- gate stack. The presence of these defects is confirmed by the study of the negative effects of a high- as a gate oxide.

Secondly, the Y function method is extended to the saturation regime to reliably extract saturation velocity, obtained in the same conditions as ION current. The problematic due to inversion charge estimation in short devices is solved using high frequency measurements with a two ports structure. Then, effective mobility, average velocity and limiting velocity are obtained in ultra-scaled devices.